Libation/FileLiberator/UNTESTED/IProcessableExt.cs
2019-11-21 23:07:06 -05:00

49 lines
1.8 KiB
C#

using System;
using System.Threading.Tasks;
using DataLayer;
using Dinah.Core.ErrorHandling;
namespace FileLiberator
{
public static class IProcessableExt
{
//
// DO NOT USE ConfigureAwait(false) WITH ProcessAsync() unless ensuring ProcessAsync() implementation is cross-thread compatible
// ProcessAsync() often does a lot with forms in the UI context
//
/// <summary>Process the first valid product. Create default context</summary>
/// <returns>Returns either the status handler from the process, or null if all books have been processed</returns>
public static async Task<StatusHandler> ProcessFirstValidAsync(this IProcessable processable)
{
var libraryBook = processable.GetNextValid();
if (libraryBook == null)
return null;
// this should never happen. check anyway. ProcessFirstValidAsync returning null is the signal that we're done. we can't let another IProcessable accidentally send this commans
var status = await processable.ProcessAsync(libraryBook);
if (status == null)
throw new Exception("Processable should never return a null status");
return status;
}
public static LibraryBook GetNextValid(this IProcessable processable)
{
var libraryBooks = LibraryQueries.GetLibrary_Flat_NoTracking();
foreach (var libraryBook in libraryBooks)
if (processable.Validate(libraryBook))
return libraryBook;
return null;
}
public static async Task<StatusHandler> TryProcessAsync(this IProcessable processable, LibraryBook libraryBook)
=> processable.Validate(libraryBook)
? await processable.ProcessAsync(libraryBook)
: new StatusHandler();
}
}